FSK Data Rollercoaster
|Frequency Range||864.878 MHz - 864.878 MHz|
|Short Description||Recording using USB; baby monitor system is NFM.|
|I/Q Raw Recording||—|
Identified as baby monitor; model unknown. FMFrequency Modulation modulated voice was received in USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) mode; recording and waterfall saved, will upload later.
Monitor sends beacon bursts while idling (6 second interval, 1.5 second burst); beacon contains audio modulation. Continuous audio transmission is volume level triggered. In most observed cases, the beacon swing alternate between left to right and right to left; after a triggered transmission, the signal will swing right twice in a row. In some cases, the beacons will continuously swing left only, except for the single beacon burst after a triggered audio transmission. I think these differing beacon swing modes describes the battery charge.